The utility model relates to a sliding type slag blocking bolt comprising a fiber cylinder and a round platform-shaped slag blocking cap, wherein a round platform-shaped cavity is formed in the fiber cylinder; an opening of the cavity is greater than the bottom of the slag blocking cap, so that the slag blocking cap can be smoothly extruded into the cavity of the fiber cylinder; a slotted hole is transversely formed in the fiber cylinder and the slag blocking cap respectively. The utility model also relates to a bolt feeding device for feeding the sliding type slag blocking bolt into a steel tapping hole, and the bolt feeding device comprises an outer sleeve provided with a chute, wherein a pull rod is arranged in the outer sleeve, and a blocking strip is arranged at the top end of the pull rod; a handle is arranged in the chute, and one end of the handle is connected with the pull rod. The sliding type slag blocking bolt and the bolt feeding device have the beneficial effects that 1, the bolt feeding device can be used for tightly blocking the sliding type slag blocking bolt on the inner wall of the steel tapping hole to ensure that the sliding type slag blocking bolt can realize a slug blocking function so as to reduce early slag; 2, the bolt feeding device can reduce the probability of touching molten steel heat radiation by operators to ensure the personal safety of the operators; 3, the sliding type slag blocking bolt is simple in structure and can realize the fast mounting.